This invention relates in general to vehicle control switch assemblies, and more specifically to control switches having an elastomeric pad.
A conventional switch bank (or array) is typically formed having a stacked (i.e., overlaid) structure. The switch bank is implemented to carry a low voltage DC signal. The switch bank is a group of normally open, single pole, single throw (NO, SP, ST) momentary contact device switches. The switch bank can include a graphic overlay having painted or printed on symbols that relate to numbers, vehicle functions, and the like depending on the application of the switch bank. For example, the overlay is disposed over an electrostatic discharge (ESD)/electromagnetic interference (EMI) shield. In another example, the overlay is disposed directly over a top membrane or elastomeric pad. The membrane has a number of contacts that align with the respective symbols when the switch bank is properly assembled.
The switch bank typically also includes a spacer disposed under the membrane. The spacer has holes that generally align with respective contacts in the membrane. A bottom membrane (or circuit board) includes circuit grids that generally align with the respective contacts such that a respective circuit is closed when a user sufficiently depresses the respective symbol. The switch bank can also include a subpanel (i.e., substrate, back cover, etc.) that generally provides physical support. The stackup or overlay of the respective symbol, contact, hole, and grid forms an individual switch in the switch bank.
The conventional switch bank has a number of deficiencies that include when the switch bank is manufactured, the layers (i.e., the overlay, the membrane, the spacer, the circuit board, and the sub-panel) can be difficult to align such that the respective symbols, holes, and circuits align properly, the switch bank is not lighted or backlit, the overlay and the symbols are not registered (i.e., the surface of the overlay is substantially smooth such that a user can not readily discern switch location and type by feel), and the switch bank does not provide tactile feedback feel to the user. Additionally, conventional switch banks, particularly rocker type switches with opposed contacts for first and second functions lack sufficient structural strength to prevent both contacts from being made when multiple forces are applied.